For travelers looking to delve deeper into the darker corners of Cambodian history, this self-guided tour is a must-see. Learn of the chilling events and darkest moments of the Khmer Rouge regime in Cambodia with a visit to the Phnom Penh Tuol Sleng Museum and Killing Fields. The tour starts with a pick-up from your hotel, and with audio guides in tow, listen to some facts about Prison S21 before actually visiting it. This location is also home to the Tuol Sleng Genocide Museum, and if you're lucky, prison survivors may drop by and interact with you as they give their first-hand testimonials about the regime. A tour staff will meet you outside when you're done and then it's off to the Killing Fields, your last stop for the day. On the way, you can keep listening to your audio guide to know more about the mass killings and burials that had happened there. The self-guided tour is a must for history buffs and anyone keen on studying this country's past, as it will give you a far deeper understanding of the shadowy regime in Cambodian heritage.